Adenoid basal carcinoma of the uterine cervix: clinicopathologic features of 12 cases with reference to CD117 expression.

Adenoid basal carcinoma is a rare tumor of the uterine cervix. Less than 100 cases have been documented thus far, and only a few cases have been reported among the Asian population. An important differential diagnosis is cervical adenoid cystic carcinoma because of their overlapping morphologic appearances but absolutely different clinical outcomes. The treatment of adenoid basal carcinoma should be conservative due to its generally benign behavior. CD117 (c-kit) have been recently found immunohistochemically positive for adenoid cystic carcinomas of other anatomic locations and may serve as a useful ancillary differential marker. CD117 expression for adenoid cystic carcinoma and adenoid basal carcinoma of the uterine cervix has never been evaluated. We report the clinicopathologic features of 12 adenoid basal carcinomas with reference to CD117 expression, which represent the largest series from the Asian population. All typical adenoid basal carcinomas are negative for CD117 or have only an equivocal staining intensity. In contrast, 1 adenoid cystic carcinoma and 1 mixed adenoid basal/cystic carcinoma of the uterine cervix are positive for CD117. CD117 may be of value in differential diagnosis between these 2 entities and guide follow-up and treatment program. Further investigation of CD117 expression in a larger series of adenoid cystic carcinoma of the uterine cervix is needed to validate this notion.